Weird issue these last few days when using the forum on Safari on Mac. as you can see in the pic, there's a huge gap between the menu bar and next lines when using Safari V10.1 on OSx 10.11.6 - well, for me there is! Having to use an alternate browser.

Clearing cache fixed that for me - for a while. Then it came back and I didn't want to re-login to all my sites so I used another machine for arduino browsing. Then, after a while I tried again and it had fixed itself - whatever bad script that was causing it had presumably dropped from cache.